Integrated circuits can include a semiconductor device and one or more bond pads that are in electrical communication with the semiconductor device. The bond pads provide electrical communication between the integrated circuit and another device that can control or utilize the integrated circuit. As an example, a respective wire may be wire-bonded to each of the bond pads to provide electrical communication between the integrated circuit and the other device.
In some integrated circuits, the bond pads are proximal to the semiconductor device such that significant, or measurable, capacitive coupling is present between the bond pads and the semiconductor device or between the bond wires and the semiconductor device. When this capacitive coupling is consistent, or predictable, it generally can be accounted for; however, when this capacitive coupling is not consistent, or predictable, it can create challenges associated with operation of the integrated circuit.
As an example, semiconductor devices, in the form of capacitive pressure sensors, can be utilized to detect a pressure. The capacitive pressure sensors rely on a capacitance measurement to detect the pressure, and a full-scale range of this capacitance measurement can be on the order of 100's of femtofarads (fF). Integrated circuits that include capacitive pressure sensors often are coated with a dielectric gel to protect the integrated circuits from environmental damage while, at the same time, permitting the capacitive pressure sensors to detect pressure forces from an ambient environment that surrounds the integrated circuit.
Air bubbles can form within the dielectric gel. When these air bubbles form proximal the capacitive pressure sensor, proximal the bond pads, or proximal the wires, they can change the capacitive coupling between the capacitive pressure sensor and the bond pads or between the capacitive pressure sensor and the wires. This change in capacitive coupling can cause shifts in the capacitance measurement of the capacitive pressure sensor that can be on the order of 10's of fF. Such shifts can make it difficult to reproducibly manufacture or calibrate integrated circuits that include capacitive pressure sensors. Decreasing the magnitude of these shifts in the capacitance measurement can improve reproducibility of manufacture or calibration of the integrated circuits.